JP4519674B2 - Filter material and cylindrical filter using the same - Google Patents

Description

  The present invention relates to a filter medium capable of filtering solids in a fluid, particularly to a filter medium capable of filtering solids in a liquid, and a cylindrical filter using the same.

  Conventionally, porous sheets such as porous membranes, non-woven fabrics, woven fabrics, and nets are known as filtering materials that can filter solids in fluids. As a cylindrical filter, these filtering materials can be used alone or in two or more types. What is wound around a cylindrical porous cylinder is known. For example, the applicant of the present invention consists of a plurality of non-woven fabrics (filter media) made of fibers produced by a melt-blow process or a jet spinning process so that the average fiber diameter and the average pore diameter become larger toward the outside of the cylindrical porous cylinder. Layered wound cartridge filters have been proposed (Patent Document 1, Patent Document 2).

JP-A-1-297113 JP-A-4-27403

  As such a filter material, a non-concave nonwoven fabric made by a conventional melt-blow process or jet spinning process was used, so that the filtration life of the cylindrical filter was limited.

  The present invention has been made to solve the above-described problems, and provides a filter medium capable of producing a filter having a longer filter life than that of a conventional filter, and a tubular filter having a longer filter life using the filter medium. The purpose is to do.

The invention according to claim 1 of the present invention is “a filter medium in which a number of irregularities are formed on a porous sheet made of thermoplastic fibers , and has a non-linearly extending convex end, and the upper end of the filter medium. As the projection extends from the lower portion to the lower end, the two convex portions merge to become one, the convex portion where the concave portion between the convex portions disappears, and the convex portion that extends from the upper end portion to the lower end portion of the filter medium. The filter medium in which the part is branched and becomes two or more, the convex part where the concave part is generated is mixed, and the concaves and convexes extend in a certain direction as a whole is disposed around the perforated cylinder, the fixed direction and the axis of the perforated cylinder A cylindrical filter characterized in that it is wound in a flat manner so as to coincide with the direction, and the upper and lower ends in the axial direction of the perforated cylinder are sealed with an upper cap and a lower cap .

The invention according to claim 2 of the present invention, "filter medium, characterized in that it further comprises a cross recess extending in a direction crossing the direction in which a large number of irregularities extending of claim 1, wherein the tubular Filter .

The invention according to claim 3 of the present invention is "the cylindrical filter according to claim 1 or 2, wherein the entire filter medium is not formed into a film . "

The invention according to claim 4 of the present invention is "the cylindrical filter according to any one of claims 1 to 3, wherein a large number of irregularities are formed by majolica pleating . " It is.

The invention according to claim 5 of the present invention is characterized in that "the porous sheet is made of a nonwoven fabric selected from meltblown nonwoven fabric, wet nonwoven fabric, spunbond nonwoven fabric, and mixed nonwoven fabric in which meltblown fibers and stretched fibers are mixed. The cylindrical filter according to any one of claims 1 to 4.

The invention according to claim 6 of the present invention is as follows: "The filter medium repeats alternately a high region and a low region of the height of the convex portion. The cylindrical filter described in 1.] .

The invention according to claim 7 of the present invention is as described in any one of claims 1 to 6, wherein a different pore diameter filter medium made of porous sheets having different average flow pore diameters is also wound. The cylindrical filter. "

The invention according to claim 8 of the present invention is the “cylindrical filter according to any one of claims 1 to 7 , further comprising a region where the filter medium is folded and folded”. .

The invention according to claim 1 of the present invention uses the surface area is wide filtration material by having a large number of irregularities, protrusion end portion extends nonlinearly, wound to the filtering material Rights However, the filter media are not in close contact with each other, and the filter media are not in close contact with each other due to the pressure during the filtration of the fluid, so there is no dead space and the large surface area of the filter media can be used effectively, the filtration flow rate is large, Moreover, Ru long fill Tadea of filtration life. In addition, because the end of the convex part extends in a non-linear shape, it has excellent shape retention, and since the micro space can be maintained while maintaining the form even during fluid filtration, clogging is unlikely to occur. it is also a long filter of filtration life.

  Since the invention concerning Claim 2 of this invention is further equipped with the cross recessed part, a surface area is still wider.

The invention according to claim 3 of the present invention, the entire filtering member is not to form a film, because the entire filter medium can participate in filtration, larger filtration flow rate, yet are long filters of filter life.

In the invention according to claim 4 of the present invention, since a large number of irregularities are formed by majolica pleating, a very large number of irregularities extending in a non-linear manner are formed, and the surface area is wide, so that the filtration life is increased. it is a long filter.

The invention according to claim 5 of the present invention, since the surface area of the porous sheet itself is wide, large filtration area can be effectively used, a long filter of filtration life.

The invention according to claim 6 of the present invention is a filter that can obtain the diffusion effect of the fluid to be filtered, can effectively use the filtration area, has a large filtration flow rate, and has a long filtration life.

  The invention according to claim 7 of the present invention is a filter having a long filtration life because it can be stepwise filtered from a solid substance having a large particle diameter by winding a different pore diameter filter medium.

  The invention according to claim 8 of the present invention is a filter having a long filtration life because it has a region where the filter medium is folded.

  The filter medium of the present invention will be described with reference to FIG. FIG. 1 is a conceptual perspective view showing a part of the filter medium of the present invention. As shown in FIG. 1, the filter medium of the present invention has a large surface area because it has a large number of convex portions and concave portions. In addition, since the end of the convex portion extends non-linearly, the filter media do not adhere to each other even when the filter media are wound, and the filter media do not adhere to each other even due to pressure during fluid filtration. Thus, it is possible to produce a filter having a large filtration flow rate and a long filtration life, in which a dead space is not generated, and a large surface area of the filter medium can be effectively used.

More specifically, the filter medium of FIG. 1 is provided with a large number of convex portions CV ₁ to CV _n , and both end portions of each convex portion extend non-linearly. For example, both the left end E _1L and the right end E _{1R toward} the convex portion CV ₁ are bent and do not extend linearly. Similarly, both the left end portion E _2L and the right end portion E _2R are bent _toward the convex portion CV ₂ and do not extend linearly. The filter medium of the present invention has a large number of such convex portions. Incidentally, the concave portion CC ₁ is formed between the left end portion _{E 2L} of the right end portion of the projecting portion CV _{1 E 1R} and the convex portion CV _2. Recess CC ₂ is formed between the similarly left end _{E 3L} of right end _{E 2R} and convex portions CV ₃ of the convex portion CV _2. As described above, the recesses CC _{1 to} CC _n−1 are formed between the protrusions CV _{1 to} CV _n . As is apparent from FIG. 1, “non-linear” in the present invention means other than a straight line, for example, a curved line, a wavy line, a bent line connecting two or more straight lines, a curved line and a straight line, A line connected regularly or irregularly can be mentioned. In addition, the convex part edge part may be mixed.

As can be seen from FIG. 1, the convex portions CV ₁ to CV _n are often not independent from the upper end portion to the lower end portion of the filter medium, and are 2 as they extend from the upper end portion to the lower end portion of the filter medium. Two convex parts may merge and become one. In other words, the recess disappears as it extends from the upper end to the lower end of the filter medium. Moreover, one convex part may branch and it may become two or more as it extends from the upper end part of a filter medium to a lower end part. In other words, a concave portion is generated on the way from the upper end portion to the lower end portion of the filter medium. Such convex portions may be mixed. However, it is preferable that the unevenness extends as a whole in a certain direction. For example, in FIG. 1, it extends in the direction indicated by the arrow L. When extending in a certain direction in this way, even if the filter medium is wound around the perforated cylinder so that the constant direction and the axial direction of the perforated cylinder coincide with each other, the concavo-convex structure is not easily destroyed and the desired filtration performance is exhibited. This is because it can.

Furthermore, filtering material of Figure 1 is provided with a cross recess CC _C1 to CC _Cm extending in a direction perpendicular to the extending direction is uneven as described above. Therefore, a filter having a wide filtration area, a large filtration flow rate, and a long filtration life can be produced. In the case where irregularities extending in a predetermined direction, so as not to reduce the winding of the filtering material, cross recess preferably is shallower depth than the recess _{CC 1} ~CC n-1. Incidentally, cross recess CC _C1 to CC _Cm in FIG. 1 is a direction orthogonal to the direction extending unevenness, need not be orthogonal. Moreover, it does not need to be straight, and may be non-linear. Furthermore, it is not necessary to be continuous, and these may be discontinuous or mixed.

Furthermore, in the filter medium of FIG. 1, the area R ₁ from the upper end of the filter medium to the intersecting recess CC _C1 has fewer projections than the area R ₂ from the intersecting recess CC _C1 to the intersecting recess CC _C2 . From another viewpoint, since the filtration area occupying the region R ₁ and the filtration area occupying the region R ₂ are the same, the convex portion in the region R ₁ is higher than the convex portion in the region R ₂ . Similarly, the region _{R 3} from intersecting recesses _{CC C2} until intersecting recesses _{CC C3} are fewer protrusions than the region _{R 2,} a high height of the convex portion. In this way, since the high and low regions of the convex portion are alternately repeated, the diffusion effect of the fluid to be filtered can be obtained, the filtration area can be used effectively, the filtration flow rate is large, and the filtration life is long. Long filters can be manufactured.

  Such a filter medium is preferably not made into a film as a whole. This is because the entire filter medium can be involved in filtration and has a wide filtration area that can function effectively, so that a filtration flow rate is large, a pressure loss during passage of fluid hardly increases, and a filter with a long filtration life can be manufactured. “Filming” refers to a state in which the fiber form is lost and the space between the fibers is closed.

  The thickness of the filter medium of the present invention, that is, the length from the convex portion to the concave portion is preferably 0.5 to 5 mm. If the thickness is less than 0.5 mm, an increase in the surface area cannot be expected so much. If the thickness exceeds 5 mm, the filter medium is easily deformed by an external force. The thickness of the filter medium of the present invention refers to a value obtained by actually measuring the length from the convex portion to the concave portion with a micrometer. As described above, when the thickness varies depending on the region, it means the thickness of the thickest region.

  The many irregularities in the filter medium of the present invention are preferably formed by majolica pleating. This is because, according to the majolica pleating process, a very large number of irregularities extending in a non-linear manner can be formed, and a filter having a long filtration life can be manufactured due to the large surface area. This majolica pleating process is a well-known technique conventionally performed in the clothing field.

  The porous sheet that is the basis of the filter medium of the present invention is preferably composed of a nonwoven fabric with a large surface area, and in particular, from among meltblown nonwoven fabrics, wet nonwoven fabrics, spunbond nonwoven fabrics, and mixed nonwoven fabrics in which meltblown fibers and stretched fibers are mixed. It is preferably made of a selected non-woven fabric. Among these, a melt blown nonwoven fabric having a large surface area is preferable. Since the melt blown nonwoven fabric is not subjected to a strong stretching action, there is an effect that the pore diameter can be easily adjusted by performing the heat treatment and the pressure treatment.

  The preferred “melt blown nonwoven fabric” refers to a nonwoven fabric obtained by a melt blow method. For example, a nozzle piece arranged with an orifice diameter of 0.1 to 0.5 mm and a pitch of 0.3 to 1.2 mm is set to a temperature of 220 to Heated to 370 ° C., 0.02-1.5 g / min. Per orifice. The melt-blown fiber is discharged at a ratio of, and the discharged melt-blown fiber can be produced by allowing a gas having a temperature of 220 to 400 ° C. and a mass ratio of 5 to 2,000 times the amount of discharged fiber to act. .

  The melt blown fiber can be composed of a thermoplastic resin, for example, a polyester resin, a polyamide resin, a polyolefin resin (for example, a polyethylene resin, a polypropylene resin, etc.), a polyvinylidene chloride resin, a polyvinyl chloride. It can be composed of one or more types such as a series resin, a polystyrene series resin, a polyacrylonitrile series resin, and a polyvinyl alcohol series resin. Among these resins, polyolefin resins (particularly polypropylene) are preferable because they are excellent in chemical resistance and versatility.

  In addition, the resin component which comprises a meltblown fiber does not need to be 1 type, and may contain 2 or more types. When the meltblown fiber is composed of two types of resin components, the cross-sectional shape can be, for example, a core-sheath type, an eccentric type, a side-by-side type, a sea-island type, an orange type, or a multiple bimetal type.

  This melt blown non-woven fabric may be used as it is by collecting and collecting melt blown fibers discharged from the orifice with a collector, and heat treatment and / or pressure treatment is carried out after collection in order to adjust the pore diameter. You may use what you did.

  Moreover, since the wet nonwoven fabric has a narrow pore size distribution, the filtration accuracy of the filter medium can be improved. This “wet non-woven fabric” means that after a fiber web is formed by a wet method, the fiber web is entangled by a fluid flow such as a water flow, or a thermoplastic fiber is contained in the fiber web and bonded by the thermoplastic fiber. Or a non-woven fabric obtained by bonding fibers together by using them together or using an emulsion binder or a latex binder. Among these, wet nonwoven fabrics which include thermoplastic fibers and are bonded with thermoplastic fibers are suitable because they have appropriate rigidity and can improve processability.

  Examples of the thermoplastic fibers include polyester resins, polyamide resins, polyolefin resins (eg, polyethylene resins, polypropylene resins, etc.), polyvinylidene chloride resins, polyvinyl chloride resins, polystyrene resins, polyresins. A fiber containing one or more kinds of resins such as acrylonitrile resin and polyvinyl alcohol resin can be used. Among these thermoplastic fibers, polyolefin fibers (particularly polypropylene fibers) are excellent in chemical resistance and versatility, and thus can be suitably used. In addition, the thermoplastic fiber does not need to be one type, and may include two or more types. The greater the content of this thermoplastic fiber, the more preferable. Specifically, it is preferably 50 mass% or more, more preferably 80 mass% or more, most preferably composed of 100 mass% thermoplastic fiber. preferable.

  Non-thermoplastic fibers (for example, regenerated fibers such as rayon fibers, semi-synthetic fibers such as acetate fibers, plant fibers such as cotton and hemp, animal fibers such as wool) are included as fibers other than these thermoplastic fibers. Also good.

  Spunbond non-woven fabric has moderate strength and is excellent in maintainability of uneven shape, prevents adhesion between filter media, does not produce dead space, and has a wide filtration area that can function effectively, so the filtration flow rate is high A large filter with a long filtration life can be manufactured. This “spunbond nonwoven fabric” refers to a nonwoven fabric obtained by a conventional spunbond method, and can be easily obtained because it is commercially available.

  The spunbond fiber constituting the spunbond nonwoven fabric can be composed of one or more kinds of resin components similar to the thermoplastic fiber constituting the wet nonwoven fabric as described above. When the spunbond fiber is made of two types of resins, the cross-sectional shape can be a core-sheath type, an eccentric type, a side-by-side type, a sea-island type, an orange type, or a multiple bimetal type.

  As this spunbond nonwoven fabric, a spunbond nonwoven fabric obtained by a conventional spunbond method may be used as it is, or a heat-treated and / or pressure-treated one may be used to adjust the pore diameter. good.

  A non-woven fabric in which meltblown fibers and drawn fibers are mixed (hereinafter sometimes referred to as “mixed non-woven fabric”) has a dense structure, but has a high filtration flow rate, excellent filtration accuracy, and a long filtration life. It has the feature that it can be manufactured. It also has the advantages of excellent strength and excellent workability.

  This mixed nonwoven fabric has an average fiber diameter (average fiber diameter at 100 or more points) produced by the melt blow method of 0.1 to 20 μm, 5 to 95 mass% of melt blown fibers, and an average fiber diameter of 10 to 100 μm. It is preferable that 95 to 5 mass% of drawn fibers are mixed.

  The conditions for producing the meltblown fibers by this meltblowing method are not particularly limited, but they can be produced under the same conditions as those for producing the aforementioned meltblown nonwoven fabric.

  This meltblown fiber can be comprised from 1 or more types of resin similar to the thermoplastic fiber which comprises the above-mentioned wet nonwoven fabric. When the meltblown fiber is made of two or more kinds of resins, the cross-sectional shape can be, for example, a core-sheath type, an eccentric type, a side-by-side type, a sea-island type, an orange type, or a multiple bimetal type.

  On the other hand, “drawn fiber” is not a fiber drawn by applying air to the fiber extruded from the nozzle, such as a melt blown fiber or a spunbond fiber, but a fiber extruded from the nozzle by a mechanical machine such as a drawing machine. A fiber drawn by action.

  The drawn fiber can be composed of one or more kinds of resins similar to the thermoplastic fiber constituting the wet nonwoven fabric as described above. When the drawn fiber is made of two or more kinds of resins, the cross-sectional shape can be, for example, a core-sheath type, an eccentric type, a side-by-side type, a sea-island type, an orange type, or a multiple bimetal type. In this way, when the drawn fiber is composed of two or more types of thermoplastic resins, the fibers can be heat-sealed if there is a difference in the melting points of the resins, and the low melting point component can be heat treated at a temperature equal to or higher than the melting point of the low melting point component. Is melted and cooled and solidified while maintaining the fiber shape with a resin component having a high melting point, and an appropriate space can be maintained by the drawn fibers. In this case, the melting point difference between the low melting point component and the high melting point component is preferably 10 ° C. or more, and more preferably 20 ° C. or more. Further, the low melting point component of the drawn fiber is preferably 10 ° C. or more lower than the melting point of the melt blown fiber (if the melt blown fiber is made of two or more resins, the melting point of the resin having the lowest melting point), and 20 ° C. or more. Low is more preferable.

  The drawn fibers may be long fibers or short fibers, but are preferably short fibers so that they can exist in a state of being uniformly mixed with meltblown fibers. In the case of a short fiber, the fiber length is preferably 5 to 160 mm, and more preferably 25 to 110 mm so as to be easily entangled with the meltblown fiber.

  This drawn fiber does not need to consist of one type, and two or more types of drawn fibers that differ in terms of fiber diameter, composition, fiber length, etc. may be used.

  Such a mixed nonwoven fabric can be manufactured as follows, for example.

  First, as shown in FIG. 2 for the production process diagram of the mixed nonwoven fabric, the spreader 3 opens the flow of the meltblown fiber 2 discharged from the meltblown apparatus 1 under the same conditions as those for producing the meltblown nonwoven fabric. After the drawn stretched fibers 4 are supplied and both are mixed, the mixed fiber group can be collected by a collecting body 5 such as a conveyor to form the mixed nonwoven fabric 6.

  Examples of the spreader 3 that supplies the drawn fiber 4 include a card machine and a garnet machine, and a spreader 3 in which a plurality of opening cylinders 31 as shown in FIG. Can cause the stretched fibers 4 to collide with the flow of the meltblown fibers 2 vigorously so that the meltblown fibers 2 and the stretched fibers 4 are evenly mixed even in the thickness direction of the mixed nonwoven fabric 6. Therefore, it is preferable.

  Further, when the drawn fiber 4 is supplied by the spreader 3, the drawn fiber 4 is supplied from a direction perpendicular to the flow of the melt blown fiber 2 so that the drawn fiber 4 can be uniformly mixed with the melt blown fiber 2. Is preferred. For example, when the flow of the meltblown fiber 2 discharged from the meltblown apparatus 1 is formed in the horizontal direction, the drawn fiber 4 may be naturally dropped and supplied from above in the direction perpendicular to the flow of the meltblown fiber 2. In general, the flow of the melt blown fiber 2 discharged from the melt blower 1 is preferably in the same direction as the direction of gravity, so that the drawn fiber 4 supplied from the fiber opening machine 3 acts on the gravity. It is preferable to supply from a direction perpendicular to the direction. In the fiber opening machine 3 of FIG. 3, the air nozzle 33 which can supply air is provided so that the stretched fiber 4 can be vigorously supplied at such an angle (right angle).

  In addition, the existence ratio of the stretched fibers 4 in the thickness direction of the mixed nonwoven fabric 6 can be changed by adjusting the angle at which the stretched fibers 4 are supplied to the meltblown fibers 2.

  The collector 5 that collects the fiber group in which the melt blown fiber 2 and the stretched fiber 4 are mixed may be a roll or a net, but the air flow that conveys the fiber group In order to prevent the mixed nonwoven fabric 6 from being disturbed or scattered by the collision, the collector 5 is preferably breathable, and an airflow suction device is preferably provided on the side opposite to the collection surface.

  The mixed nonwoven fabric 6 produced in this way may be used as it is, and it is preferable to adjust the average flow pore size by carrying out heat treatment and / or pressure treatment. The heat treatment and the pressure treatment may be performed simultaneously, or the pressure treatment may be performed after the heat treatment is performed. In FIG. 2, the fusion-mixed nonwoven fabric 8 can be formed by heating and pressing with the heating and pressing apparatus 7.

  The filter medium of the present invention can be used as a filter medium for a filter for filtering a solid substance from a gas, or can be used as a filter medium for a filter for filtering a solid substance from a liquid. More specifically, filtration of fluid filters such as liquids used or liquids used in each manufacturing process such as food / beverage, electronics, medicine, chemistry, water treatment, photography, paint, plating, dyeing, machinery / steel, etc. Can be used as a material.

The filter medium of the present invention is a porous sheet that is the basis of the filter medium, preferably melt blown nonwoven fabric, wet nonwoven fabric, spunbond nonwoven fabric, mixed nonwoven fabric in which melt blown fibers and stretched fibers are mixed, and then extends non-linearly. It can be manufactured by forming a large number of projections and depressions having the ends of the projections. As described above, it is preferable that the unevenness is formed so as not to be formed into a film, and is a filter medium having no filmed portion. As a method for forming the unevenness, for example, a method of embossing at a temperature at which the porous sheet is not formed into a film using an embossing roll, various pleating machines used in the clothing field (majorica pleating machine, And a method using an irregular pleating machine). Among these, as described above, it is preferable to use a majolica pleat processing machine. According to this majolica pleat processing machine, the convex portions CV ₁ to CV _n as shown in FIG. 1 are not independent from the upper end portion to the lower end portion of the filter medium, and extend from the upper end portion to the lower end portion of the filter medium. Therefore, the filter medium in which the two convex portions merge to become one, the filter medium in which one convex portion branches into two or more as they extend from the upper end portion to the lower end portion of the filter material, and these are mixed. Filter medium, filter medium with irregularities extending in a certain direction as a whole, filter medium with intersection recesses CC _{C1 to} CC _Cm in the direction in which the recesses and protrusions extend, and an intersection having a shallower depth than the recesses CC _{1 to} CC _n-1 A filter medium having a recess, a filter medium in which a high area and a low area of a protrusion are alternately repeated, and a filter medium not entirely formed into a film can be easily manufactured.

  The cylindrical filter of the present invention is obtained by winding the above-described filter medium around a porous cylinder. As described above, since the filter medium has the protruding end that extends in a non-linear manner, the filter medium is not in close contact with the pressure during winding or the pressure during filtration. Therefore, it is a filter having a large filtration flow rate and a long filtration life, in which a dead space does not occur and a large surface area of the filter medium can be used effectively. In addition, since the end of the convex portion extends in a non-linear manner, it has excellent shape retention, and since the micro space can be maintained while maintaining the form even during fluid filtration, clogging is less likely to occur. Is a long-life filter.

  The cylindrical filter of the present invention is exactly the same as the conventional one except that the filter medium of the present invention is used. That is, the filter medium of the present invention is wound around the porous cylinder, and the upper and lower ends in the axial direction of the cylindrical filter are the upper cap and the lower cap, respectively, and the end of the filter medium is sealed, The outflow of fluid from the part is prevented. Such a cylindrical filter can be manufactured by winding a filter medium around a porous cylinder and then sealing the upper and lower axial ends of the cylindrical filter with an upper cap and a lower cap, respectively.

  Another cylindrical filter of the present invention has an average flow pore size different from that of the porous sheet, which is the basis of the uneven filter material, in addition to the above-described filter medium (hereinafter sometimes referred to as “uneven filter medium”). A different pore diameter filter medium made of a porous sheet is also wound. This cylindrical filter is also a filter with a long filtration life because the irregular filter material is wound, and the particle size to be filtered can be divided by the irregular filter material and the different pore diameter filter material, and clogging is unlikely to occur. . The porous sheet constituting the different pore diameter filter material only needs to have an average flow pore diameter different from that of the porous sheet constituting the irregular filter material, and the different pore diameter filter material has a large number of irregularities and extends in a non-linear manner. May be provided, or may have a large number of irregularities and be provided with convex end portions that extend linearly, or may be smooth without irregularities (the porous sheet itself). There may be. If the average flow pore size of the porous sheet constituting the different pore size filter medium is smaller than the average flow pore size of the porous sheet constituting the irregular filter material, the different pore size filter material is wound downstream in the fluid flow direction. If the average flow pore diameter of the porous sheet constituting the different pore diameter filter material is larger than the average flow pore diameter of the porous sheet constituting the uneven filter medium, the particle diameter is increased by winding upstream in the fluid flow direction. It is preferable to be able to filter sequentially from solids. However, the uneven filter material and the different pore diameter filter material may be alternately wound. In addition, the difference in average flow hole diameter is not particularly limited. The “average flow pore size” in the present invention refers to a value obtained by a method defined in ASTM-F316, and can be measured by a bubble point method using, for example, a porometer (Polometer, manufactured by Coulter). The porous sheet constituting the different pore diameter filtering material is also composed of a melt blown nonwoven fabric, a wet nonwoven fabric, a spunbond nonwoven fabric, or a mixed nonwoven fabric in which melt blown fibers and stretched fibers are mixed, similar to the porous sheet that is the basis of the uneven filter material. Is preferred.

  The cylindrical filter of the present invention is exactly the same as the conventional one except that the uneven filter material of the present invention and the different pore diameter filter material are wound. That is, the uneven filter material and the different pore diameter filter material of the present invention are wound around the porous cylinder, and the upper and lower caps in the axial direction of the cylindrical filter are the upper cap and the lower cap, respectively. The end of the material is sealed, and the fluid can be prevented from flowing out from the end of the uneven filter material and the different pore diameter filter material. Such a cylindrical filter can be manufactured by winding an uneven filter material and a different pore diameter filter material around a porous tube, and then sealing the axial upper and lower ends of the cylindrical filter with an upper cap and a lower cap, respectively.

  Still another cylindrical filter of the present invention includes a region in which the filter medium is folded in addition to the region in which the uneven nonwoven fabric as described above is wound (hereinafter sometimes referred to as “winding region”) ( Hereinafter, it may also be referred to as “fault region”. Since this cylindrical filter is provided with a winding area and a folded area, it has excellent filtration performance with desired filtration accuracy, filtration flow rate, and filtration life. Note that the filter medium in the folded region may be the same as the uneven filter material in the winding region in terms of the uneven state, the manufacturing method, and / or the average flow pore size, or may be a different uneven filter material. good. Moreover, the filter medium provided with the convex part edge part extended linearly may be sufficient, and the smooth filter medium (namely, porous sheet) without an unevenness | corrugation may be sufficient. In addition, the average flow pore diameter of the filter material in the folded region (the porous sheet before forming the unevenness in the case of unevenness) is larger than the average flow pore size of the porous sheet under the uneven filter material in the winding region. If it is small, a folded region is arranged downstream in the fluid flow direction, and the average flow pore size of the filter material in the folded region (the porous sheet before forming the unevenness when it has unevenness) is wound. When the average flow pore size of the porous sheet under the uneven filter material in the region is larger than the average flow pore size of the porous sheet, it is possible to arrange a fracture region on the upstream side in the fluid flow direction so that filtration can be performed in order from solids with larger particle sizes. Is preferable. The porous sheet constituting the filter material constituting the folded region is the same melt blown nonwoven fabric, wet nonwoven fabric, spunbond nonwoven fabric, or melt blown fiber as the porous sheet that is the basis of the uneven filter material constituting the winding region. It is preferably made of a mixed nonwoven fabric in which stretched fibers are mixed.

  This cylindrical filter is exactly the same as the conventional one except that it has a wound region and a folded region around which the uneven nonwoven fabric of the present invention is wound. That is, it comprises a wound region in which a concavo-convex filter material is wound around a porous tube and a folded region in which the filter material is folded, and the upper and lower ends in the axial direction of the tubular filter are respectively an upper cap and The uneven cap material constituting the winding region and the end portion of the filter material constituting the folded region are sealed by the lower cap, and the fluid from the end portion of the wound region constituting the uneven filter material and the folded region constituting filter material is sealed. It has a structure that can prevent outflow. In such a cylindrical filter, after forming the winding region of the uneven filter material and the folded region of the filter material around the porous tube, the upper end and the lower end in the axial direction of the cylindrical filter are respectively connected to the upper cap and the lower cap. Can be sealed and manufactured.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

(Preparation of porous sheet)
(1) Production of mixed nonwoven fabric;
A nozzle piece having an orifice diameter of 0.2 mm and a pitch of 0.8 mm arranged with orifices is heated to a temperature of 320 ° C., and 0.06 g / min. Polypropylene resin is discharged at a ratio of about 70 ° C., and air is applied to the discharged polypropylene resin at a temperature of 330 ° C. and 70 times the resin discharge amount by mass ratio, and the average fiber diameter is the same as the direction of gravity action. A flow of 1.8 μm polypropylene meltblown fiber 2 (melting point: 160 ° C.) was formed.

  The two opening cylinders 31 as shown in FIG. 3 are accommodated in the housing 32 from a direction perpendicular to the flow of the polypropylene melt blown fibers, and the core component is polypropylene from the opening machine 3 provided with the air nozzle 33. A core-sheath type thermoplastic stretched short fiber 4 having a fiber diameter of 21.6 μm and a fiber length of 38 mm, which is made of a resin (melting point: 160 ° C.) and whose sheath component is made of polyethylene resin (melting point: 135 ° C.), is made of the above polypropylene. Mixed with meltblown fiber 2. In addition, the mixing mass ratio of the polypropylene melt blown fiber 2 and the core-sheath type thermoplastic stretched short fiber 4 was (polypropylene meltblown fiber 2) :( core-sheath type thermoplastic stretched short fiber 4) = 65: 35. .

  A mixed fiber web was formed by collecting a fiber group in which the melt blown fiber 2 made of polypropylene and the core-sheath type thermoplastic short staple fiber 4 were mixed with a conveyor belt. The conveyor belt was made of a mesh body, and air was sucked from the side opposite to the belt collecting surface by a gas suction device to prevent disturbance of the fibers constituting the mixed fiber web.

Then, the mixed fiber web was performed for 3 minutes heat treatment by dryer temperature 145 ° C. atmosphere, by bonding only the sheath component of the sheath-core thermoplastic stretch short fibers 4, basis weight 50 g / m ^2, thickness 0 A mixed non-woven fabric having an average flow rate pore diameter of 13.7 μm was manufactured.

(2) Production of pressure mixed nonwoven fabric;
Nozzle pieces having orifice diameters of 0.2 mm and pitches of 0.8 mm were heated to a temperature of 320 ° C., and 0.04 g / min. Polypropylene resin is discharged at a rate of 340 ° C., air is applied to the discharged polypropylene resin at a temperature of 340 ° C. and 80 times the resin discharge amount by mass ratio, and the average fiber diameter is the same as the direction of gravity action. A flow of 1.5 μm polypropylene meltblown fiber 2 (melting point: 160 ° C.) was formed.

  The two opening cylinders 31 as shown in FIG. 3 are accommodated in the housing 32 from a direction perpendicular to the flow of the polypropylene melt blown fibers, and the core component is polypropylene from the opening machine 3 provided with the air nozzle 33. A core-sheath type thermoplastic stretched short fiber 4 having a fiber diameter of 21.6 μm and a fiber length of 38 mm, which is made of a resin (melting point: 160 ° C.) and whose sheath component is made of polyethylene resin (melting point: 135 ° C.), is made of the above polypropylene. Mixed with meltblown fiber 2. In addition, the mixing mass ratio of the polypropylene melt blown fiber 2 and the core-sheath type thermoplastic stretched short fiber 4 was (polypropylene meltblown fiber 2) :( core-sheath type thermoplastic stretched short fiber 4) = 65: 35. .

  A mixed fiber web was formed by collecting a fiber group in which the melt blown fiber 2 made of polypropylene and the core-sheath type thermoplastic short staple fiber 4 were mixed with a conveyor belt. The conveyor belt was made of a mesh body, and air was sucked from the side opposite to the belt collecting surface by a gas suction device to prevent disturbance of the fibers constituting the mixed fiber web.

Next, this mixed fiber web was heat-treated for 3 minutes with a dryer at a temperature of 145 ° C., and only the sheath component of the core-sheath type thermoplastic stretched short fiber 4 was adhered, and the basis weight was 105 g / m ² and the thickness was 0. A mixed nonwoven fabric having a diameter of .48 mm and an average flow pore size of 4.3 μm was produced.

Next, the mixed nonwoven fabric is passed between a pair of rolls composed of a metal roll and a resin roll (temperature: 80 ° C., linear pressure: 0.8 kN / cm) to have a basis weight of 105 g / m ² and a thickness of 0.20 mm. A pressure mixed nonwoven fabric with an average flow pore size of 1.6 μm was produced.

(3) Production of uneven nonwoven fabric A;
Unevenness was formed in the above-mentioned (1) mixed nonwoven fabric with a majolica pleating machine, and unevenness mixed nonwoven fabric A was manufactured. This uneven mixed nonwoven fabric A was provided with a large number of convex portions, and both ends of each convex portion extended in a curved state. In addition, a convex part is not independent from the upper end part of the uneven | corrugated mixed nonwoven fabric A to a lower end part, and two or more convex parts merge as it extends from an upper end part to a lower end part, and the convex part which joined is 2. While repeating the branching into one or more about every 1 cm, as a whole, the uneven mixed nonwoven fabric A extended from the upper end to the lower end. In addition, a boundary that repeats that two or more protrusions merge and that the merged protrusion branches into two or more continuously extends in a straight line in a direction orthogonal to the direction in which the unevenness extends. , Provided with a cross recessed portion shallower than the recessed portion. In addition, since the two or more convex portions joined regularly and the joined convex portions branched into two or more regularly, the region where two or more convex portions joined has the number of convex portions. There are few areas where the merged protrusions branch into two or more, so the number of protrusions is large, so the area where two or more protrusions merge is more convex than the area where the merged protrusions branch into two or more. The height was high, 1.1 mm. Furthermore, the uneven mixed nonwoven fabric A was not made into a film as a whole.

(4) Production of uneven nonwoven fabric B;
The above described (1) mixed nonwoven fabric B was produced by passing between a pair of rolls composed of an embossing roll and a flat roll (temperature: 80 ° C., linear pressure: 0.6 kN / cm). This uneven mixed nonwoven fabric B was provided with rhombus-shaped recesses in a staggered pattern, and the total recess area ratio was 28%. Moreover, the thickness of the convex part was 0.33 mm, and the concave part was formed into a film.

(5) Production of uneven nonwoven press mixed nonwoven fabric;
Unevenness was formed in the above-mentioned (2) pressure-mixed non-woven fabric using a majolica pleat processing machine to produce a press-mixed non-woven fabric. This uneven pressurization mixed nonwoven fabric was provided with a large number of convex portions, and both ends of each convex portion were extended in a curved state. In addition, a convex part is not independent from the upper end part of a uneven | corrugated pressurization mixed nonwoven fabric to a lower end part, and two or more convex parts merge as it extends from an upper end part to a lower end part, While repeating the branching into two or more approximately every 1 cm, the whole extended from the upper end portion of the uneven pressurizing mixed nonwoven fabric toward the lower end portion. In addition, a boundary that repeats that two or more protrusions merge and that the merged protrusion branches into two or more continuously extends in a straight line in a direction orthogonal to the direction in which the unevenness extends. , Provided with a cross recessed portion shallower than the recessed portion. In addition, since the two or more convex portions joined regularly and the joined convex portions branched into two or more regularly, the region where two or more convex portions joined has the number of convex portions. There are few areas where the merged protrusions branch into two or more, so the number of protrusions is large, so the area where two or more protrusions merge is more convex than the area where the merged protrusions branch into two or more. The height was high, 1.0 mm. Furthermore, the uneven pressurizing mixed nonwoven fabric was not entirely made into a film.

(6) Production of pressure melt blown nonwoven fabric A;
A nozzle piece having an orifice diameter of 0.3 mm and a pitch of 0.8 mm arranged with orifices was heated to a temperature of 330 ° C., and 0.33 g / min. Polypropylene resin is discharged at a ratio of about 240 ° C., and melt blown fibers formed by applying 240 times the amount of resin discharged at a temperature of 330 ° C. and a mass ratio to the discharged polypropylene resin are accumulated on a conveyor. (Distance between nozzle piece and conveyor: 49 cm) A meltblown fiber web was produced.

Next, the meltblown fiber web is passed between a pair of rolls (temperature: 80 ° C., linear pressure: 0.5 kN / cm) composed of a metal roll and a resin roll, and the basis weight is 80 g / m ² and the thickness is 0.00. A pressure melt blown nonwoven fabric A having a diameter of 15 mm, an average fiber diameter of 1.7 μm, and an average flow pore diameter of 1.9 μm was produced.

(7) Production of uneven pressure melt blown nonwoven fabric A;
Unevenness was formed in the above-mentioned (6) pressure melt blown nonwoven fabric A with a majolica pleating machine, and the uneven pressure meltblown nonwoven fabric A was manufactured. This uneven pressure melt blown nonwoven fabric A was provided with a large number of convex portions, and both ends of each convex portion extended in a curved state. In addition, a convex part is not independent from the upper end part of the uneven | corrugated pressurization melt blown nonwoven fabric A to a lower end part, and as it extends from an upper end part to a lower end part, two or more convex parts merge, and the convex part which merged As a whole, it extended from the upper end part of uneven | corrugated pressurization melt blown nonwoven fabric A toward the lower end part, repeating that branching into two or more about every 1 cm. In addition, a boundary that repeats that two or more protrusions merge and that the merged protrusion branches into two or more continuously extends in a straight line in a direction orthogonal to the direction in which the unevenness extends. , Provided with a cross recessed portion shallower than the recessed portion. In addition, since the two or more convex portions joined regularly and the joined convex portions branched into two or more regularly, the region where two or more convex portions joined has the number of convex portions. There are few areas where the merged protrusions branch into two or more, so the number of protrusions is large, so the area where two or more protrusions merge is more convex than the area where the merged protrusions branch into two or more. The height was high, 0.7 mm. Furthermore, the uneven pressure melt-blown nonwoven fabric A was not film-formed as a whole.

(8) Production of pressure melt blown nonwoven fabric B;
A nozzle piece having an orifice diameter of 0.3 mm and a pitch of 0.8 mm arranged with orifices was heated to a temperature of 330 ° C., and 0.33 g / min. Polypropylene resin is discharged at a rate of about 300 ° C., and melt blown fibers formed by applying 230 times the amount of resin discharged at a temperature of 330 ° C. and a mass ratio to the discharged polypropylene resin are accumulated on a conveyor. (Distance between nozzle piece and conveyor: 49 cm) A meltblown fiber web was produced.

Next, the meltblown fiber web is passed between a pair of rolls (temperature: 80 ° C., linear pressure: 0.3 kN / cm) composed of a metal roll and a resin roll, and the basis weight is 80 g / m ² and the thickness is 0.00. A pressure melt blown nonwoven fabric B having a diameter of 20 mm, an average fiber diameter of 2.0 μm, and an average flow pore diameter of 3.1 μm was produced.

(9) Production of melt blown nonwoven fabric A;
A nozzle piece having an orifice diameter of 0.3 mm and a pitch of 0.8 mm arranged with orifices was heated to a temperature of 330 ° C., and 0.33 g / min. Polypropylene resin is discharged at a rate of about 300 ° C., and melt blown fibers formed by applying air at a temperature of 330 ° C. and 200 times the resin discharge amount to the discharged polypropylene resin are accumulated on a conveyor. (distance between the nozzle piece and the conveyor: 49cm), basis weight 80 g / ^{m 2,} thickness 0.9 mm, average fiber diameter of 2.1 .mu.m, to produce a melt-blown nonwoven fabric a of the mean flow pore size 5.0 .mu.m.

(10) Production of melt blown nonwoven fabric B;
A nozzle piece having an orifice diameter of 0.3 mm and a pitch of 0.8 mm arranged with orifices was heated to a temperature of 315 ° C., and 0.33 g / min. Polypropylene resin is discharged at a rate of 315 ° C., and melt blown fibers formed by applying air of 150 times the resin discharge amount at a temperature of 315 ° C. and a mass ratio to the discharged polypropylene resin are accumulated on a conveyor. (Distance between nozzle piece and conveyor: 49 cm) A melt blown nonwoven fabric B having a basis weight of 80 g / m ² , a thickness of 1.0 mm, an average fiber diameter of 3.9 μm, and an average flow pore diameter of 10.2 μm was produced.

(11) Production of melt blown nonwoven fabric C;
Nozzle pieces having orifice diameters of 0.3 mm and pitches of 0.8 mm were heated to a temperature of 320 ° C., and 0.33 g / min. Polypropylene resin is discharged at a rate of, and melt blown fibers formed by applying air that is 200 times the resin discharge amount at a temperature of 320 ° C. and a mass ratio to the discharged polypropylene resin are accumulated on a conveyor. (Distance between nozzle piece and conveyor: 49 cm) A melt blown nonwoven fabric C having a basis weight of 80 g / m ² , a thickness of 1.0 mm, an average fiber diameter of 3.2 μm, and an average flow pore diameter of 7.9 μm was produced.

(12) Production of melt blown nonwoven fabric D;
A nozzle piece having an orifice diameter of 0.3 mm and a pitch of 0.8 mm arranged with orifices is heated to a temperature of 300 ° C., and 0.33 g / min. Polypropylene resin is discharged at a rate of 300 ° C., and melt blown fibers formed by applying air of 120 times the resin discharge amount at a temperature of 300 ° C. and a mass ratio to the discharged polypropylene resin are accumulated on a conveyor. (Distance between nozzle piece and conveyor: 49 cm) A melt blown nonwoven fabric D having a basis weight of 80 g / m ² , a thickness of 1.0 mm, an average fiber diameter of 7.6 μm, and an average flow pore diameter of 20.2 μm was produced.

(13) Internet preparation;
A polypropylene net (weight per unit: 34 g / m ² , thickness: 0.25 mm, unity: 1 mm × 2 mm) was prepared.

(14) Production of melt blown-spunbond composite nonwoven fabric (MS composite nonwoven fabric);
A polypropylene spunbond nonwoven fabric having a basis weight of 15 g / m ² , a thickness of 0.2 mm, an average fiber diameter of 37 μm, and an average flow pore diameter of 50 μm, prepared by a conventional spunbond method, was prepared.

  On the other hand, a nozzle piece having an orifice diameter of 0.3 mm and a pitch of 0.8 mm and having orifices arranged thereon was heated to a temperature of 330 ° C., and 0.33 g / min. The melt-blown fiber made of polypropylene (melting point: 160 ° C.) is discharged at a rate of 330 ° C., and the air is applied to the discharged melt-blown fiber at a temperature of 330 ° C. and 220 times the fiber discharge amount in mass ratio. (Distance between nozzle piece and conveyor: 49 cm) to produce a meltblown fiber web.

Next, the melt blown fiber web was heat-treated with a dryer at a temperature of 130 ° C., and then pressed under the condition of a linear pressure of 0.3 kN / cm to have a basis weight of 30 g / m ² , a thickness of 0.17 mm, and an average fiber. A melt blown nonwoven fabric having a diameter of 2.1 μm and an average flow pore size of 14.5 μm was produced.

Next, the polypropylene spunbond nonwoven fabric and the melt blown nonwoven fabric were integrated by ultrasonic sealing to produce an MS composite nonwoven fabric having a basis weight of 45 g / m ² , a thickness of 0.36 mm, and an average flow pore size of 14.0 μm.

(15) Production of uneven M-S composite nonwoven fabric;
Unevenness was formed in the above-mentioned (14) MS composite nonwoven fabric with a majolica pleating machine to produce an unevenness MS composite nonwoven fabric. This uneven | corrugated MS composite nonwoven fabric was equipped with many convex parts, and it extended in the state in which the both ends most part of each convex part curved. In addition, a convex part is not independent from the upper end part of an uneven | corrugated MS composite nonwoven fabric to a lower end part, and two or more convex parts merge as it extends from an upper end part to a lower end part, and the convex part which merged Branching into two or more portions every about 1 cm, and extending from the upper end portion of the concave-convex MS composite nonwoven fabric toward the lower end portion as a whole. In addition, a boundary that repeats that two or more protrusions merge and that the merged protrusion branches into two or more continuously extends in a straight line in a direction orthogonal to the direction in which the unevenness extends. , Provided with a cross recessed portion shallower than the recessed portion. In addition, since the two or more convex portions joined regularly and the joined convex portions branched into two or more regularly, the region where two or more convex portions joined has the number of convex portions. There are few areas where the merged protrusions branch into two or more, so the number of protrusions is large, so the area where two or more protrusions merge is more convex than the area where the merged protrusions branch into two or more. The height was high, 1.2 mm. Furthermore, the entire concave-convex MS composite nonwoven fabric was not formed into a film.

(16) Production of pressurized wet nonwoven fabric;
A sea-island fiber (fineness: 1.65 dtex, fiber length: 3 mm) obtained by a composite spinning method in which 25 island components made of polypropylene are present in a sea component made of poly-L-lactic acid was prepared. Next, this sea-island fiber was immersed in an aqueous solution of sodium hydroxide at a temperature of 80 ° C. and 10 mass% for 30 minutes to extract and remove poly-L-lactic acid, which is a sea component of the sea-island fiber, to obtain polypropylene ultrafine fibers (average Fiber diameter: 1.8 μm, melting point: 172 ° C., cut fiber length: 3 mm).

  On the other hand, as an adhesive fiber, a core-sheath type composite adhesive fiber (fiber diameter: 11) whose core component is made of polypropylene (melting point: 158 ° C.) and whose sheath component (adhesion component) is made of high-density polyethylene (melting point: 131 ° C.). .8 μm, cut fiber length: 10 mm).

Next, the polypropylene microfiber and the core-sheath type composite adhesive fiber are dispersed in a dispersion bath made of water at a mass ratio of 50:50, made by a paper machine, dried at a temperature of 140 ° C., and simultaneously the core-sheath. Only the adhesive component of the mold composite adhesive fiber was adhered to produce a wet nonwoven fabric having a basis weight of 38 g / m ² , a thickness of 0.34 mm, and an average flow pore size of 12.1 μm.

Next, the wet nonwoven fabric is passed between a pair of rolls composed of a metal roll and a resin roll (temperature: 80 ° C., linear pressure: 1.5 kN / cm), and the basis weight is 38 g / m ² , the thickness is 0.12 mm, A pressurized wet nonwoven fabric having an average flow pore size of 4.5 μm was produced.

(17) Preparation of uneven pressurizing wet nonwoven fabric;
Concavities and convexities were formed on the above-mentioned (16) pressurized wet nonwoven fabric with a majolica pleat processing machine to produce an uneven pressurized wet nonwoven fabric. This uneven pressurizing wet nonwoven fabric was provided with a large number of convex portions, and both ends of each convex portion extended in a curved state. In addition, a convex part is not independent from the upper end part of an uneven | corrugated pressurization wet nonwoven fabric to a lower end part, and two or more convex parts merge as it extends from an upper end part to a lower end part, and the convex part which merged is While repeating the branching into two or more about every 1 cm, the whole extended from the upper end portion of the concavo-convex pressure wet nonwoven fabric toward the lower end portion. In addition, a boundary that repeats that two or more protrusions merge and that the merged protrusion branches into two or more continuously extends in a straight line in a direction orthogonal to the direction in which the unevenness extends. , Provided with a cross recessed portion shallower than the recessed portion. In addition, since the two or more convex portions joined regularly and the joined convex portions branched into two or more regularly, the region where two or more convex portions joined has the number of convex portions. There are few areas where the merged protrusions branch into two or more, so the number of protrusions is large, so the area where two or more protrusions merge is more convex than the area where the merged protrusions branch into two or more. The height was high, 0.7 mm. Furthermore, the uneven pressurizing wet nonwoven fabric was not entirely made into a film.

Example 1
(6) Pressurized meltblown nonwoven fabric A so that the left end of the above-mentioned (3) unevenness-mixed nonwoven fabric (220 cm long) is 40 cm from the left end of the aforementioned (6) pressurized meltblown nonwoven fabric A (40 cm) Next, (8) Pressurized meltblown on the (3) uneven mixed nonwoven fabric so that the right end of the (6) pressurized meltblown nonwoven fabric A and the left end of the (8) pressurized meltblown nonwoven fabric B coincide with each other. The non-woven fabric B is laminated, and then (9) the melt-blown non-woven fabric A on the (3) concavo-convex mixed non-woven fabric so that the right end of the (8) pressure melt-blown non-woven fabric B and the left end of the (9) melt-blown non-woven fabric A coincide with each other. And (10) the above-mentioned (10) melt on the uneven mixed nonwoven fabric so that (9) the right end of the meltblown nonwoven fabric A and (10) the left end of the meltblown nonwoven fabric B coincide with each other. By laminating blow nonwoven fabric B, to produce a filtered material laminate. Hereinafter, the filter medium laminate is described in the order of a nonwoven fabric that is a base having a length of 220 cm and a nonwoven fabric that is laminated in order from the left end side of the nonwoven fabric that is the base. In the case of the above-mentioned filter material laminate, (3) Concavity and convexity mixed nonwoven fabric- (6) Pressurized meltblown nonwoven fabric A- (8) Pressurized meltblown nonwoven fabric B- (9) Meltblown nonwoven fabric A- (10) Meltblown nonwoven fabric B To do.

  Next, the filter material laminate is wound in a flat shape from the left end so that the surface on which the (6) pressure melt blown nonwoven fabric A or the like of the filter material laminate is laminated is disposed inside the polypropylene porous cylinder. After that, a polypropylene cylindrical outer cylinder (outer diameter: 70 mm) was attached to the outer side of the wound filter material laminate. Thereafter, an upper cap and a lower cap made of polypropylene were bonded to both end faces in the length direction of the perforated tube to produce a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm.

(Example 2)
(1) Mixed nonwoven fabric- (7) Uneven pressure melt blown nonwoven fabric A- (8) Pressurized melt blown nonwoven fabric B- (9) Melt blown nonwoven fabric A- (10) Melt blown nonwoven fabric B, 1) Implemented except that the length of the mixed non-woven fabric was 320 cm long, and (1) 80 cm from the left end of the mixed non-woven fabric and (7) the left end of the uneven pressure melt-blown non-woven fabric A were aligned. In the same manner as in Example 1, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was produced.

(Comparative Example 1)
Except that (13) Net- (6) Pressurized meltblown nonwoven fabric A- (8) Pressurized meltblown nonwoven fabric B- (9) Meltblown nonwoven fabric A- (10) Meltblown nonwoven fabric B was used as the filter media laminate. A cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was produced in the same manner as in Example 2.

(Comparative Example 2)
Except that (12) melt blown nonwoven fabric D- (6) pressurized melt blown nonwoven fabric A- (8) pressurized melt blown nonwoven fabric B- (9) melt blown nonwoven fabric A- (10) melt blown nonwoven fabric B was used as the filter material laminate. In the same manner as in Example 1, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was produced.

(Comparative Example 3)
Except for using (1) mixed nonwoven fabric- (6) pressurized melt blown nonwoven fabric A- (8) pressurized melt blown nonwoven fabric B- (9) melt blown nonwoven fabric A- (10) melt blown nonwoven fabric B as the filter media laminate, In the same manner as in Example 2, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was manufactured.

(Comparative Example 4)
Other than using (4) uneven mixed nonwoven fabric B- (6) pressurized melt blown nonwoven fabric A- (8) pressurized melt blown nonwoven fabric B- (9) melt blown nonwoven fabric A- (10) melt blown nonwoven fabric B as the filter media laminate Produced a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm in exactly the same manner as in Example 2.

(Example 3)
(15) Uneven M-S composite nonwoven fabric-(2) Pressurized mixed nonwoven fabric-(8) Pressurized meltblown nonwoven fabric B- (9) Meltblown nonwoven fabric A- (10) Meltblown nonwoven fabric B as the filter media laminate Except for the above, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was manufactured in the same manner as in Example 1.

Example 4
(14) M-S composite non-woven fabric-(5) Uneven pressure-mixed non-woven fabric-(8) Pressurized melt blown non-woven fabric B-(9) Melt blow non-woven fabric A- (10) Melt blow non-woven fabric B Except for the above, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was manufactured in the same manner as in Example 2.

(Comparative Example 5)
Other than using (14) MS composite nonwoven fabric-(2) Pressurized mixed nonwoven fabric-(8) Pressurized meltblown nonwoven fabric B- (9) Meltblown nonwoven fabric A- (10) Meltblown nonwoven fabric B as the filter media laminate Produced a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm in exactly the same manner as in Example 1.

(Example 5)
Except for using (15) Uneven M-S composite nonwoven fabric-(16) Pressurized wet nonwoven fabric-(9) Melt blow nonwoven fabric A-(11) Melt blow nonwoven fabric C-(10) Melt blow nonwoven fabric B as the filter media laminate In the same manner as in Example 1, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was produced.

(Example 6)
Except for using (14) MS composite nonwoven fabric-(17) uneven pressurizing wet nonwoven fabric-(9) melt blown nonwoven fabric A-(11) melt blown nonwoven fabric C-(10) melt blown nonwoven fabric B as the filter material laminate. In the same manner as in Example 2, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was produced.

(Comparative Example 6)
Except for using (14) MS composite nonwoven fabric-(16) pressurized wet nonwoven fabric-(9) melt blown nonwoven fabric A-(11) melt blown nonwoven fabric C-(10) melt blown nonwoven fabric B as a filter material laminate. In the same manner as in Example 2, a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 70 mm, and a length of 250 mm was manufactured.

(Various performance evaluation)
(A) Water flow resistance Using each cylindrical filter, the pressure loss when water was flowed at a flow rate of 25 L / min was measured to obtain water flow resistance.

(B) Filtration accuracy A test solution having a concentration of 10 ppm in which JIS test powders (11 types; Kanto Loam) were dispersed in water was prepared, and each cylindrical filter was supplied with a flow rate of 10 L / min. (Examples 1-4, Comparative Examples 1-5), or 25 L / min. In Examples 5 to 6 and Comparative Example 6, water was passed from the outside to the inside, and the filtrate after 1 minute of water flow was collected. About the powder contained in this filtrate and the test liquid before filtration, the particle number according to particle size was measured using the particle size distribution measuring device (Coulter Multisizer ll by COULTER).

The filtration efficiency for each particle size was calculated from the following formula, and the particle size at which the filtration efficiency was 100% was defined as the filtration accuracy of the cylindrical filter.
Filtration efficiency (%) = {(Bn−An) / Bn} × 100
Here, Bn means the number of particles in the test solution before filtration, and An means the number of particles in the filtrate.

(C) Filtration life 10 ppm (Examples 1 to 4, Comparative Examples 1 to 5) or 100 ppm (Examples 5 to 6 and Comparative Examples) in which powders for JIS testing (8 types; Kanto Loam) were dispersed in water The test solution of 6) is prepared, and the flow rate is 10 L / min (Examples 1 to 4, Comparative Examples 1 to 5) or 25 L / m (Examples 5 to 6 and Comparative Example 6) to each cylindrical filter while stirring. ), And the pressure loss was measured. The total amount of water processed until the pressure difference from the initial pressure loss reaches 100 kPa (Examples 1 to 4, Comparative Examples 1 to 5) or 200 kPa (Examples 5 to 6 and Comparative Example 6) is filtered. It was.

  These results were as shown in Tables 1 and 2.

  From Table 1 and Table 2, the cylindrical filter using the filter medium of the present invention was excellent in that the water flow resistance was low and the filtration life was long.

Conceptual perspective view showing a part of the filter medium of the present invention Manufacturing process diagram of mixed nonwoven fabric Cross section of spreader

Explanation of symbols

1 meltblowing apparatus 2 meltblown fibers 3 opener 4 drawn fibers 5 collecting member 6 mixed nonwoven fabric 7 heating and pressing treatment apparatus 8 fused mixed nonwoven 31 opening cylinder 32 housing 33 air nozzles CV ₁ ~CV _n protrusion E _nL protrusion CV _n region from the top portion to the intersection recess _{CC C1} on the left side of the end portion E _nR protrusion right side of the end portion CC ₁ ~CC _n-1 recess CC _C1 to CC _Cm cross recess R ₁ filter medium CV _n of R _n Region from the intersecting recess CC _{C (n−1)} to the intersecting recess CC _Cn L Direction in which the protrusion extends

Claims (8)

A filter medium to form a large number of irregularities in the porous sheet made of thermoplastic fibers, provided with a protrusion end portion extending non-linearly as it extends to the lower portion from the upper end of the filtration material, two convex The protrusions are merged into one, and the protrusion between the protrusions disappears, and the protrusion extends from the upper end portion to the lower end portion of the filter medium. The filter medium in which the convex portions where the occurrence occurred is mixed and the unevenness extends as a whole in a certain direction is flatly wound around the perforated tube so that the certain direction and the axial direction of the perforated tube coincide with each other. A cylindrical filter characterized in that the upper and lower ends in the axial direction of the cylinder are sealed with an upper cap and a lower cap. The cylindrical filter according to claim 1 , wherein the filter medium further includes an intersecting concave portion extending in a direction intersecting with a direction in which a large number of irregularities extend . The cylindrical filter according to claim 1 or 2, wherein the entire filter medium is not formed into a film . The cylindrical filter according to any one of claims 1 to 3, wherein a number of irregularities are formed by majolica pleating . The porous sheet is made of a nonwoven fabric selected from meltblown nonwoven fabric, wet nonwoven fabric, spunbonded nonwoven fabric, and mixed nonwoven fabric in which meltblown fibers and stretched fibers are mixed. The cylindrical filter as described in 2 . The cylindrical filter according to any one of claims 1 to 5, wherein the filtering material alternately repeats a region having a high convex portion and a region having a low convex portion. The cylindrical filter according to any one of claims 1 to 6, wherein a filter medium with different pore diameters made of porous sheets having different average flow pore diameters is also wound. The cylindrical filter according to any one of claims 1 to 7 , further comprising a region in which the filter medium is folded in a folded manner.

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